Aircraft propulsion device



Owls-'1946' 1. 'M L. DQNNELLAN 2,409,552

AIRCRAFT PnoruLrsIoN DEvIcE Filed may 27.' 1943 C s sheets-sheet z A? n las W* SQ@ Oct. 15, 1946. M. l.. DONNELLAN 2,409,552

` AIRCRAFT PRoPULsIoN DEVICE Filed may 27. 1945 3 sheetsfsneet s Z,/ maag@ 9KB/YQ@ Patented Oct. 15, 1946 PATENT OFFICE AIRCRAFT PROPULSION DEVICE .Maurice L. Dcnnellan, Ypsilanti, Mich.

Application May 27,

2 Claims. `1

The present invention relates to an aeronautical take-off device and more 'particularly to a device which is adapted to assist in the take-off of air borne vehicles. An air borne vehicle of the rigid wing type is least efcientvmechanically during its take-,off period. `At this time the weight oi theplane andits load is supported'by the landing gear and the ground engaged wheels. In order to attain ight speed'it is necessary to have the vehicle and its load rapidly accelerated in order to attain such speeds as to impart a lift to the wing. During .the Ytake-ofi period it usually -is necessary to move .the vehicle over a relatively.7 great distance which requires'the entire power output of the ymotors Vbecause of the excessive power demands during `thematic-off interval. As is known, .actual 4iiight `of the -vehicle when air borne requires A.considerably `less than the entire power out-put ofthe motors. K

It is, thereforef amongftheobjects. of fthe .present invention: i

l. To provide a-novel aeronautical take-01T device to `furnish additional -power to the lplane during the take-offperiod. l

2. To provide a" novel aeronautical tal e-oii de vice which maybe readily attached to the plane while-on the ground but Ywhich isdetached from the plane as soon as take-off speeds are attained and the plane becomes air borne.

3. To provide a novel take-off device consisting of a vehicle havingground engaged wheels which are power driven independently of the motors of the aircraft, thus `permitting relatively greater loads in the aircraft while permitting a take-01T from a restricted area without requiring the use of additional motors on the planeitself.

4. To provide .a device :particularly adapted for handling and maneuvering ground borne aircraft and in which the .powerlis eiliciently applied'directly to the ground contacting wheels'of the aircraft.

5. T provide Yan aeronautical .take-oil' device which will minimize the requirement of highlift characteristics oi the wing and permitthe design oi" wings having relatively higher speed characteristios without increasing the dimensions re*- duired inthe take-oir area.

6. To provide a novel aeronautical take-off device in which the horse power available for the take-01T `may be selectively increased as maybe required to' assure a proper take-oni within the space and time interval available. 'l'. To provide a device to assist in the take-off of air borne vehicles, either of the power driven or the motorless glider types` either singly or in multiples, such for example as in trains.

8. To provide a device adapted to supply aux` iliary power to a normallyair-borne vehicle duringthe take-ofi` and in which the power developed 1943, 'serial No. 488,763

Y 2 in the take-off device is transmitted -eiciently directly to the wheels of the plane.

Other objects or this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part oi this speciiic'ation wherein like reference characters designate corresponding parts of the several views. p

Fig. 1 is a view in side elevation showingan airplane 'with a take-oit device of the present invention connected therewith, parts of Vtheplane being broken away to show details of control mechanism used-with the present invention.

Fig. 2 is a fragmentary top plan view taken substantially along the `line Z-Z in the direction of the arrows in Fig. 1.

Fig. 3 is a top'plan View with sidesbroken away and partially in section showing a take-oit device embodying the present invention. u

Fig. 4 is an enlarged fragmentary side elevation of the take-ofi device embodying the present invention.

Fig. 5 is an enlarged vsectional view'taken sub--` stantially along the linet5--5looking in the directionof the arrows inFig. 3.

Fig. Gis an enlarged fragmentary sectional view taken substantially along-the line 6-5 looking vin the direction of the arrows in Fig. 3.

Fig. '7 is an enlarged sectional detail of the attaching mechanism taken intheencircled area 1 of Fig. 4. I

Fig. `8 is a fragmentary plan view taken substantially along the line 8-8 in the direction of the arrows of Fig. `3.

Fig.` 9 `is a fragmentary sectional view taken along the Vline 9-9 looking in the direction of the arrows of Fig. 3.

Before explaining in detail thepresent inven-l tion, it is to be understood that the invention `is not limited in its application to the details of construction and arrangement of parts illustrated in theaccompanying drawings, since the invene tion is capable of other embodiments and of being practiced or vcarried out in various ways. Also` it is to be understood that the phraseology -or terminology employed herein is for the purpose of description `and not of limitation. p

In the preferredembodiment of the presentinvention, I propose to utilize a power driventakeoi device on each of the ground engaging land ing wheels of the airplane and to synchronize their operation as will hereinafter `be more fully described. In order to simplify the drawings and the Vdescription of the invention, it will be described with reference to but one take-oit device arranged fordriving one of the ground engaging wheels of the airplane, it being understood that the other units which engage they other ground engaging wheels of the airplane will be .identical in construction and operation with lthat to be u hereinafter described. It is also to be understood that it is within the scope of the present invention to utilize but a single take-olf device of the present invention and by the provision of a plurality of spaced driving heads to drive more than one of the ground engaging wheels of the plane at one time.

Referring to the drawings, and particularly to Fig. 1, I designates an airplane of conventional design, which is provided with a landing gear I I which carries a plurality of ground engaging wheels I2, one of which only is shown in the drawings. A vertically pivoted rudder I3 is provided to control the movement of the plane horizontally, the rudder being controlled by the pilot of the plane in accordance with conventional practice and construction.

The take-olf device of the present invention is indicated in general by the numeral I4 and is provided with a pair of ground engaging drive wheels I5, operatively connected and power driven by a suitable source of power I6, such for example as an internal combustion engine, a Diesel engine, a gas-electric drive, or the like. The take-olf device I 4 is guided by manipulation of front steering wheels or, preferably the single steering wheel I'I, which is mounted in forks I8 (see Fig. 6) which are pivotally connected as will be hereinafter more fully described, with the frame I9. While the single wheel has definite advantages as to maneuverability, it is to be understood that a pair of steering wheels may be used in accordance with any desired conventional design or construction.

Steering movement of the wheel I'I is effected by a manually controlled steering gear 2U, when the device is disconnected from the plane. When connected with the plane, the take-on' device I4 is guided by the steering arm 2 I.

Power is transmitted from the take-olf device I4 to the plane wheel I2 by a power driven gear member 22, which is connected by suitable gearing with a power driven shaft 23, which is operatively connected for the transmission of driving torque to the power source I6. The driven gear member 22 is preferably a solid member provided with resilient gear teeth, as shown. If desired, however, it may have rigid gear teeth, or it may be a pneumatic tire member mounted on a wheel secured to an axle. As shown in Fig. 3 the power source I6 is connected with a transmission 24 having a power take-olf 25 which is connected through bevel gearing 26 to drive the shaft 23. A shaft 21 is driven from the transmission 24 and transmits driving torque through a conventional type of differential 28 to the power driven axle 29, which drives the ground engaging driving wheels I5. Control and shifting mechanism 30 is provided for selectively declutching or driving the wheels I and is controlled from a shift control 3| whichis placed adjacent the operators seat in the device. A shift control 32 also placed ad jacent the operators seat in the device controls the selective declutching or driving of the power take-off shaft 23 and the gear member 22. The driving torque of the shaft 23 is transmitted through bevel gears 33 to the member 22 and drives the ground engaging wheel I 2 of the plane.

The driving member 22 is mounted on a shaft carried by pivotally mounted arms 34 and 35, which are provided with vertical adjusting members 34-A and 35-A by means of which either end of the shaft may be raised or lowered independently of the other end by the pivoting of the arm 34 and 35. By this provision the angular .relation of the driving member 22 to the ground engaging wheel I2 of the plane may be varied so as to compensate for the camber and caster of the wheel I2. In this way an aligned meshing of the gear teeth on the member 22 with the ribbed portions of the tread 36 on the wheel I2 is effected as shown in greater detail in Fig. 9.

This provides a positive power drive from the member 22 to the wheel I2.

In order to assure the accurate meshing of the ribbed portion of the driving member 22 with the ribbed portion of the tread 36, means are provided for removing accumulations of earth, stones, and the like or similar substances from the spaces between the resilient ribbed portions of the tread 36. In a preferred embodiment of the invention, I provide jets 46 of a high velocity fluid, such as water, which are supplied with such uid under pressure through a fluid supply line 4I, which is connected with a pressure pump 42 driven by a motor 43, and supplied with the fluid from a iiuid supply tank 44. Where the tread of the tire I2 is of rubber and the driving member 22 has gear teeth members also of rubber of suitable hardness to transmit a drive from one member to the other, the use of water either with or without a soapy lubricant is preferred for this purpose as this also lubricates the resilient gearing during the driving engagement of the member 22 and the tread 36.

In order to assure a cleaning of the spaces between the ribbed portion of the tread 36, a rotary brush 45 is provided which contacts the tread 36 and mechanically removes the greater part of the material accumulated between the ribbed portions of the tread so that the subsequent ushing with the fluid under pressure is effective to clean thoroughly the spaces between the ribbed portions of the tread 36. If it is desired to cool the tread 36 after the driving engagement with the member 22, a plurality of air jets 46 are provided for playing on the tread 36, and these jets are supplied with air under pressure from an air supply line 41 which is operatively connected with a compressed air tank 48 which is supplied with compressed air by an air compressor 49 which is driven by a motor 50.

If desired, however, either the fluid or the air or both may be dispensed with under :certain operating conditions, and also may be reversed as to their point of discharge relative to the tread 36 of the wheel I2.

The transfer of power to drive the wheel I2 is effected through a power head which preferably includes the resiliently toothed member 22, having ribs which mesh directly with the resilient rib construction on the tread 36. Alignment of the driving member 22 relatively to the tread 36 is facilitated and the member 22 is guided by means of a circumferential rib 5I, which is provided on the tire 36 and which extends vertically above the plane of the angular ribs 52. A central cut-away or beveled portion 53 is preferably provided on the member 22 for engagement 0f the riib 5I. While the present drawings show the use of but one power head on a take-olf device I4, it is to be understood that a plurality of spaced power heads may be provided, one adjacent each of the ground engaging wheels of the plane for driving such wheels, or one or more adjacent each wheel.

If a more positive drive is desired, a modified form of power head may be employed, such for example as that shown in Fig. 4. As herevshown, a spiral gear is mounted on the wheel I2 and vplane -landing gear IVI.

encanta is l-driveniby a "toothed Lgear 6 I, iwhich is carried in the .power headportion .of ithefta'ke-.off device I4, asfa'substitute `forthe member y22. Otherwise the construction ofthepower 'head and its operation is "substantially the 'same as that previously described.

A further vmodiiication is within the contemplation of the present invention and includes `a toothed `gear mounted on the wheel I2, .which maybe of any desired "type of gear design. A driven :gear 'is mounted on a gear bracket with its :teeth in mesh with theteeth of 'the saidgear. This Iportion of 'the unit would remain on "the airplane "and the ipower ihead provided rin the take-off gear I4 would consist ionly of lasplined shaft which would mesh withthe said drive `gear and would be 'selectively attached to or detached from driving relation with said 'gear as might be desired "in 'the operation of .the device.

As shown infFiggG, the steering wheel Il ofV the powertake-off device Iii of the present invention preferablyis mountedin forks "I8 which are pivotally mounted in aibracketBZ which is secured at its ends tothe frame I9. As shown in Figs. 1 and '4, thesteering gear :20 comprises a worm gear 63 vsecured ktothe steering post 64 androtated therewith. Atoothed gear segment 65 is locked to the stubshaft '66 Whichis secured to theiorks I6. Thetoothed'gear 65 meshes with the worm Agear "63. Thus upon rotation .of the worin gear V63 the forks +8 are rotated `and the Wheel yII :is Adirected as may be desired. When the take-oir device i4 :is'connectedwith the plane as shown in Figs. 1, 3 and 4, the steering movement of the wheel I'I is controlled Foy the steering-arm -ZI Whichcontrols `the movement ofthe forks I8.

The `arm 2l is provided with a forked end i'I which engages the forks I8. The `arm 2| is detachably connected with the internally toothed sleeve 'Iil -carried on a bracket 1 I secured to the Angular movement of the landing `gear -I'i relative to the power take-oli device l causes a swinging-movementiof the arm 2|, which effects a rotatio-nof the forks'and the movement of thesteering wheel I'I as may be required to direct the take-off device I4 in vsuch a direction as to Ymaintain an aligned driving relation with the wheel I2 of the airplane. 1f desired Aan over-running clutch of any conventional design (not shown) may be provided lfor connecting the forks I8 and the :stub-shaft Borso that movement of the forks AI8 -by the steering arm-2I `would be accommodated by such a clutch and not be transmitted rearwardly through the steering gear mechanism.

Theisteering arm 2I `also provides the means foredetachably connecting-the take-oit devicev I'4 with the landing gear II of the plane as shown in Figs. 4 and 7. VAs here shown Van internally toothed sleeve "i0 is secured to a bracket 'II which is carriedby the landing gear. As shown in Fig. '7 the end of the arm 2I is `provided with a spring pressed ratchet locking dog 12, which `engages with ratchet teeth I3 which are "providedinside the sleeve l! `and prevents an unintended disconnection of the plane andthe 'take-off device. A pivotally mounted4 control member 14 is adapted tocontrolfthe "locking'and unlocking of the dog 12 and the ratchet teeth 13. The control member I4 iscontrolled by la' control rod 15, which extends into the cab of the take-ofdevice I4, and is manually actuated bythe operator of the take-01T device when it is desired to disconnect the takeoff Ldevice 'from the plane or to hold the locking 6 dog 'I2 in a withdrawn position duringithe cou` plingt'of'the device "I4 to the sleeve "I0 carried by the 'landing gear.

Disconnection of the steering arm 2I is feffected by actuation .of the pivotally mounted 'control member T4 so asto `disengage fthe locking 'dog -12 from :theratchet teeth "I-3. This permits lth'e sleeve ilo to be "Ldra'wn awayffrom the end of the arm '21 and disconnects the plane and ithe takeoff device.

.In Vvorder *to synchronize the operation Aof .the takeeoif devices :I4 an electrical signalling system is 'provided which vis :controlled from the plane and transmits `visible :signals to the operators fof the power driven take-off units. An'electrically conductive `cable is provided `on each take-off device and has a quick-detachableplug 8| connected with a .receptacle 82 carried on the plane 'Ille .receptacles are electrically connected .by electrically conductive 'cables 83 with a control 84 .on -the plane instrument `.panel and are connected by .anelectrically `conductive cable `85 with theelectricallswitchmembers 85 and 8l disposed respectively, one on each iside of the movable rudder I3.

The control 8'4 operates 'a stoplampsignal 88 'and a go-'1a`mp'signal 89, which'a're provided on :the dash of each of the take-off vehicles (Fig. 8). Thus `the pilotiof the plane, vby operation lof the control B4 can signal the operators of feach of the take-off vehicles `I4when to stop and when fto fgof The switch members fB'B iandvS'I lare connected with an amber lamp signal' to call fora retarding of the "speed of 'the take-off device I4 .and with algreen signal'lamp SI to'fcall for accelerating the spe'edof the take-off device I4. Theis'ignais are synchronizedfin such a way in the takeoT .devices that when the planes rudder I3 is moved 'tto cause the plane to move to the right, anfamber signalLisflashedV to the operator of the take-off Adevice "I'l which isdriving the right wheel and1agree`n shgnal is flashed tothe operator of the take-'off device I`4 on the left wheel. This results in a speeding up of the left vwheel with relation'to the driving of the right wheel and this causes the plane to move tothe right. When movement to the `left is desired, the amber signal lamp flashes in the take-off device I4 driving the left wheel, andthe green signal lamp flashes on thedash'of thetake-off devicevoperating on the right wheel. This causes the Vplane to Vmove to theleft.

The present application is related to my copending applications Serial Nos. Il83,6l2 and 483,613 but `ciilers :from the device as shown in said applications in that :in all embodiments of the :present invention a power drive is applied directly to the vground engaging wheels of the airplane .and the take-off fdevices I4 are but Van auxiliary power source.

If desired the power `driven wheels I5 of the take-#off device r4 nmay he power driven by the motor I6 during the driving of the wheel I2, but thepre'ferred operation is to usethe `power driving ofthe wheels I5 solely for the maneuvering of theltake-of devices *I4 intodriving position with relation to theiground engaging wheels i2. .After thec'onnection of the device is effected by means of the steering arm 2I,the drive tothe power driven wheels Miris disconnected by actuation of thel'control Lmember 31| and 'the declutching memberlll. `Pit:thevsarce time `the control `member 312 is actuated so .as 4to :provide apower drive `of the driving member 22. Thus the take-offidevic'e 7 I4. is in eiect towed by the plane and all of the power from the power source I6 is transmitted directly to the tread of the ground engaging wheels I2.

If desired a plurality of connecting arms 2| may be provided to secure a more positive alignment of the power driving member carried by the power head of the take-ofi device M with the tread portion of the ground engaging wheels I2 of the plane.

If desired, however, the wheels I may be power driven and exert a push either on the wheels or the axle of the landing gear of the'plane. This may be accomplished by the use of any suitable type of push rod, yoke or fork secured to the take-ofi device i4 and having an end portion adapted for contacting a portion of the wheel oraxle of the planes landing gear.

Also it is to be understood that various types of mechanical connector and disconnector devices may be used to provide the means for accomplishing the connection and disconnection of the steering arms 2l with the airplane. Also it is to be understood that other types of signalling devices than those herein disclosed may be employed. For example, a suitable radio or telephonic connection may be established between the'plane and the take-off devices which would assure proper control of the take-ofi devices during the take-01T of the airplane.

By the present invention it will be seen that means are provided to secure an effective and efficient transfer of driving torque directly to the ground engaging wheels of the plane from auxiliary power units not directly carried by the plane. This provides a very eil'cient way in which to supply power to the plane so that the plane and its load are rapidly accelerated to take off speeds by the direct application of power to the ground engaging wheels. This additional power is readily available without increasing appreciably the weight ofthe landing gear or of the airplane and without requiring the use of permanently installed additional power units in the airplane.

Devices of the present nature are particularly useful for the assisting in the take-olf of large airplanes from restricted areas. The currently proposed sea-dromes which are floating steel landing ilelds anchored at suitable positions in the ocean, are designed to facilitate the use of large cargo and passenger carrying planes for trans-oceanic travel. Such sea-dromes are of necessity of limited dimension and devices such as that herein disclosed would be very useful in assisting in the take-off of large heavily loaded planes from the restricted areas of such seadromes. While use of such devices on a seadrome is a spectacular and timely instance of uses for the device of the present invention, it is to be understood that the device is applicable generally to assist in the take-off of large heavily loaded airplanes from any take-oil? area of restricted dimensions.

It is also to be understood that one or more of the steering arms 2| may be used either alone or in combination with a towing arm the function of which would be that of towing the take-off device I4 from the plane. Any desired combination of steering arms and towing arms may be used within the contemplation of the present invention. Such a combination would be of particular value where a positive gear drive is employed for driving the ground engaging wheel of the airplane.

It is also to be understood that any desired number of driving members 22 may be employed for driving the wheel I2. The use of combinations of two, four or six small driving wheels which may be located at spaced points on the tread of the wheel I2 is desirable under certain conditions. By the application of power to such small driving wheels, the larger wheel would be rotated evenly by power applied at such spaced points and the take-off device I4 would be more denitely aligned therewith. The provision of the spaced driving wheels also would assure the transmission of the driving torque over a larger surface area than is the case where a single driving member is employed.

While I have shown conventional types of gear mechanisms for the transmission of power from the source of power IS to the various points for power application, itis to be understood that any desired type of power transmitting device may be employed instead of positive gear devices. For example the power unit I 6 may be connected with a suitable hydraulic unit and the transmission of power to the various power driven portions of the device may be effected by suitable hydraulic power lines and torque converting devices. Also the power unit IG may be directly connected with an electric generating device and the power transmitted by suitable electric wiring directly to electric motors which are located at the points where power application is desired. All such means of transmitting power are Within the purview and scope of the present invention.

I claim:

1. A take-off device to assist in the horizontal take-oil movement of airplanes and comprising in combination a frame, a plurality of power driven wheels, a steerable wheel, a steering arm attached to said device for steering said steerable wheel, a power head, and a power source, means for selectively driving said power driven wheels and said power head from said power sourcep means for effecting a positive driving connection an airplane, and comprising a power driven toothed gear member driven by the power source and meshed in driving relation with gear tooth members provided on the landing wheel of an airplane, and quick detachable means for selectively coupling and uncoupling said steering arm and the airplane landing gear.

2. A quickly detachable power driven take-oil device to assist in the horizontal take-off movement of an airplane, said device comprising a frame, a plurality of power driven wheels secured at one end of said frame, a single steerable wheel mounted in a fork pivotally mounted on the opposite end of said frame, a power source, a power head mounted on said frame adjacent said steering wheel and lmeans for operatively connecting said power driven wheels and said power head with said power source, means for effecting a positive driving connection between said power head and a landing wheel of an airplane, a steering arm connected with said fork, a quick detachable coupling on the airplane landing gear for selectively coupling and uncoupling said arm and the airplane landing gear, said steering arm when coupled in said coupling being adapted to steer said steerable wheel and maintain a predetermined alignment of said take-off device and the airplane landing wheel at all times during the take-ofi` movement of the airplane.

MAURICE L. DONNELLAN. 

